Multilayer optic device and system and method for making same

ABSTRACT

An optic device, system and method for making are described. The optic device includes a first solid phase layer having a first index of refraction with a first photon transmission property and a second solid phase layer having a second index of refraction with a second photon transmission property. The first and second layers are conformal to each other. The optic device may be fabricated by vapor depositing a first layer and then vapor depositing a second layer thereupon. The first layer may be deposited onto a blank or substrate. The blank or substrate may be rotated during deposition. Further, a computer-controlled shutter may be used to alter the deposition rate of material along an axis of the optic device. Alternatively, the optic device may be moved at varying speeds through a vapor stream to alter the deposition rate of material.

BACKGROUND

The invention relates generally to optics, and more particularly tomultilayer optic devices and methods for making the same.

Numerous applications exist that require a focused beam ofelectromagnetic radiation. For example, energy dispersive X-raydiffraction (EDXRD) may be used to inspect checked airline baggage forthe detection of explosive threats or other contraband. Such EDXRD maysuffer from high false positives due to weak diffracted X-ray signals.The weakness of the X-ray signals may stem from a variety of origins.First, the polychromatic X-ray spectrum used in EDXRD is produced by theBremsstrahlung part of the source spectrum, which is inherently low inintensity. Second, X-ray source may collimation eliminate more than99.99 percent of the source X-rays incident on the baggage volume underanalysis. Third, some of the materials being searched for, e.g.,explosives, may not diffract strongly as they are amorphous. Fourth, thediffracting volume may be small. The last two limitations arise from thetype of threat materials being searched for in baggage, making all butthe second limitation unavoidable.

At lower X-ray energies, such as 80 keV and below, increasing thepolychromatic X-ray flux density at the material being inspected hasbeen addressed by coupling hollow glass polycapillary optics to lowpowered, sealed tube (stationary anode) X-ray sources. An example ofhollow glass polycapillary optics may be found in, for example, U.S.Pat. No. 5,192,869. The glass is the low index of refraction material,and air filling the hollow portions is the high index of refractionmaterial. These types of optics typically do not provide much gain atenergy levels above 80 keV, since the difference in the indices ofrefraction between air and glass becomes increasingly small as energylevels approach and surpass 80 keV.

Further, such optics use a concept of total internal reflection toreflect X-rays entering the hollow glass capillaries at appropriateangles back into the hollow capillaries, thereby channeling a solidangle of the source X-rays into collimated or focused beams at theoutput of the optic. As used herein, the term “collimate” refers to thecreation of quasi-parallel beams of electromagnetic (EM) radiation fromdivergent EM beams. Only about five percent of an EM source's solidangle typically is captured by the input of such known optics.

In addition, the use of air in known optics as one of the materialsprevents such optics from being placed within a vacuum. Thus, knownoptics are limited in their potential uses.

It would thus be desirable for a device that could collect more of theprimary electromagnetic radiation source and redirect those rays to adesired spot to improve the electromagnetic radiation flux density atthat spot.

BRIEF DESCRIPTION

The invention includes embodiments that relate to an optic device fortransmitting photons through total internal reflection. The optic deviceincludes at least three conformal solid phase layers. Interfaces betweenthe solid phase layers are gapless. Further, the at least threeconformal solid phase layers include at least two photon redirectionregions.

The invention includes embodiments that relate to an optic device forredirecting, through total internal reflection, photons having an energyabove one keV. The optic device includes a first solid phase layerhaving a first index of refraction and a second solid phase layer havinga second index of refraction.

The invention includes embodiments that relate to a system for focusingphotons through total internal reflection. The system includes a sourceof photons and an optic device including at least three conformal solidphase layers. Interfaces between the solid phase layers lack void areas.Further, the at least three conformal solid phase layers include atleast two photon redirection regions.

The invention includes embodiments that relate to a method for formingan optic. The method includes forming a first solid phase layer,characterized by a first index of refraction, onto a blank and formingon the first solid phase layer a second solid phase layer, characterizedby a second index of refraction. Between the first solid phase layer,the blank, and the second solid phase layer are at least two photonredirection regions.

These and other advantages and features will be more readily understoodfrom the following detailed description of preferred embodiments of theinvention that is provided in connection with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic view illustrating the phenomenon of total internalreflection.

FIG. 2 is a top schematic view of an optic device constructed inaccordance with an embodiment of the invention.

FIG. 3 is a cross-sectional view of the optic device of FIG. 2 takenalong line III-III.

FIG. 4 is a side schematic view of the optic device of FIG. 2.

FIG. 5 is a perspective view of the optic device of FIG. 2.

FIG. 6 is a perspective view of an optic device constructed inaccordance with an embodiment of the invention.

FIG. 7 is a perspective view of an optic device constructed inaccordance with an embodiment of the invention.

FIG. 8 is a perspective view of an optic device constructed inaccordance with an embodiment of the invention.

FIG. 9 is a perspective view of an optic device constructed inaccordance with an embodiment of the invention.

FIG. 10 is a perspective view of an optic device constructed inaccordance with an embodiment of the invention.

FIG. 11 is a perspective view of an optic device constructed inaccordance with an embodiment of the invention.

FIG. 12 is a perspective view of an optic device constructed inaccordance with an embodiment of the invention.

FIG. 13 is a schematic view of a deposition assembly constructed inaccordance with an embodiment of the invention.

FIG. 14 is a schematic view of a deposition assembly constructed inaccordance with an embodiment of the invention.

FIG. 15 illustrates process steps for fabricating an optic device inaccordance with an embodiment of the invention.

DETAILED DESCRIPTION

Embodiments of the invention described herein utilize the phenomenon oftotal internal reflection. Referring to FIG. 1, when an angle ofincidence is less than a critical angle θ_(c), total internal reflectionoccurs. The critical angle θ_(c) for total internal reflection dependson, among other factors, the material, the difference in the relativeindices of refraction, and the energy of the incident photons.

Referring now to FIGS. 2-5, there is shown a multilayer optic 10including an input face 12 and an output face 14. By “multilayer” ismeant a structure that has a plurality of monolayers. As shown moreparticularly in FIGS. 3 and 4, the multilayer optic 10 includes multiplelayers of material, each having a different index of refraction. Forexample, there are layers 16, 20, and 24 surrounding a core 50. Layer 16is positioned radially exterior to and contiguous with the core 50. Thecore 50 may be formed of a higher index of refraction material such asberyllium, lithium hydride, magnesium, or any other suitable elements orcompounds having similarly higher refractive indices and high X-raytransmission properties. The core 50 be less than a micrometer togreater than one centimeter in diameter. Layer 20 is positioned radiallyexterior to layer 16 and radially interior to layer 24 and contiguouswith both layers 16 and 24.

In one embodiment, the layers making up the multilayer optic 10 may beformed of materials that have varying indices of refraction. Forexample, layers 15, 19, 23 and 27 may be formed of materials that have alower index of refraction and a high photon absorption. For example, forhigh energy X-rays, appropriate materials may be chosen from osmium,platinum, gold, or any other suitable elements or compounds havingsimilarly lower refractive indices and high X-ray absorption properties.Further, the core 50 and layers 16, 20 and 24 may be formed of materialshaving a higher index of refraction and a high photon transmission. Forexample, for high energy X-rays, appropriate materials may be chosenfrom beryllium, lithium hydride, magnesium, or any other suitableelements or compounds having similarly higher refractive indices andhigh X-ray transmission properties. The diameter of the core 50 isdetermined by the critical angle for total internal reflection betweenthe higher index of refraction of the core 50 and the lower index ofrefraction of the layer 16.

By using alternating lower and higher index of refraction materials withconcurrent high and low X-ray absorption properties, respectively, incontiguous layers, the multilayer optic 10 can utilize the principle oftotal internal reflection of electromagnetic radiation. Specifically,diverging electromagnetic radiation beams 36, 38, 40, and 42 containingphotons and stemming from an electromagnetic radiation source 34 enterthe input face 12 and are redirected into quasi-parallel beams ofphotons 44 exiting the output face 14.

Multilayer optics in accordance with embodiments of the invention, suchas optic 10, can collect a large solid angle of an X-ray source 34 andredirect polychromatic energies into quasi-parallel photon beams.“Quasi-parallel” means that diverging beams of photons have beencollected and focused into beams of electromagnetic radiation or photonsto exit the output face 14 at or below the critical angle θ_(c). Thisdivergence causes the X-ray beam to be larger than the output face 14 ofthe optic 10. Alternatively, multilayer optics in accordance withembodiments of the invention may be configured to produce slightlyfocused, highly focused, slightly diverging, or highly diverging beams.By “slightly focused” is meant that the beam size at the point ofinterest (i.e., where the diameter of the beam is of concern) isapproximately the same as at the output face 14 of the optic 10. By“highly focused” is meant that the beam size at the point of interest issmaller than at the output face 14 of the optic 10. By “slightlydiverging” is meant that the beam size is larger than a quasi-parallelbeam but smaller than the intrinsic source beam. By “highly diverging”is meant that the beam is the same size or larger than the intrinsicsource beam.

The composition of materials making up the multilayer optic 10, themacroscopic geometry of the multilayer optic 10, the thickness of themultilayer optic 10, and the number of individual layers determine theangular acceptance range of the multilayer optic 10. The angularacceptance range may be from about 0 steradians up to about 2πsteradians of a solid angle of a source of the photons. For ease ofillustration, only a few layers have been illustrated with reference tomultilayer optic 10. However, it should be appreciated that any numberof layers, including into the hundreds, thousands, or millions oflayers, can be fabricated to utilize total internal reflection to formthe various types of photon beams listed previously.

Another feature of the multilayer optic 10 is that the core 50 and thelayers 16, 20, 24 have photon redirection regions. For example, layer 16has a photon redirection region 17 stemming from a center of curvature;layer 20 has a photon redirection region 21 stemming from a secondcenter of curvature; and, layer 24 has a photon redirection region 25stemming from yet another center of curvature. The photon redirectionregions 17, 21, 25 are chosen to allow for the diverging electromagneticradiation beams 36, 38, 40, and 42 to be made parallel or near parallel,or conversely to allow for parallel or converging electromagneticradiation beams to be made diverging. The minimum photon redirectionregion is determined by the minimum thickness that would still enable asmooth surface, which is at least two atomic layers, or about tenangstroms. The photon redirection regions 17, 21, 25 each containredirecting segments. The redirecting segments are chosen such that theyeach have a constant curvature. The curvature of each redirectingsegment may be the same as or different from the curvatures of otherredirecting segments. If each of the redirecting segments for aparticular photon redirection region is straight, then the radius ofcurvature is infinite.

By curving the multilayers 16, 20, 24 at the input side of the optic 10,the photons or electromagnetic radiation 36, 38, 40, 42 entering theinput face 12 can be redirected into parallel pencil beams 44, therebyincreasing the photon flux density at the output face 14 over the photonflux density in the direct source beam at the same distance from thesource 34. Depending upon the number of layers in the multilayer optic,there may be a photon density gain for 100 keV photons of as much as5000 times in the electromagnetic radiation output from the multilayeroptic over the output of conventional pinhole collimators. It should beappreciated that, alternatively, the output face 14 may be formed closerto the input face 12, i.e., positioned prior to the region where thephotons are redirected into parallel rays, allowing the inputelectromagnetic radiation beams 36, 38, 40, 42 to remain somewhatdiverging as they exit the output face 14. It should further beappreciated that core 50 and any number of the layers may have no arc ofcurvature, instead having a cylindrical cross-sectional profile.Finally, it should be appreciated, and as illustrated in FIG. 5, thatadditional layers can be formed contiguous with those described andillustrated in FIGS. 3 and 4.

An important feature of this optic 10 is that the layers can be madethin enough and the overall optic length (from input face 12 to outputface 14) short enough that photons are redirected through bounces alongonly one side of a particular layer, for example, layer 24. This isunlike known optics, where the photons bounce off both sides of aparticular layer. The fewer number of bounces needed to redirect thephotons in this multilayer optic 10 significantly increase the photontransmission efficiency of the optic 10.

Another feature of the multilayer optic 10 is that through fabricationtechniques that will be described in detail below, the individual layerscan be formed conformally on one another. The conformation of the layersenables the multilayer optic 10 to be utilized in a vacuum environment.Prior art optics utilize air as the higher refractive index material.Such optics cannot be used in vacuum environments. Further, themultilayer optic 10 can be utilized in applications that operate atenergy levels above 60 keV, such as, for example, X-ray diffraction,explosive detection, industrial X-ray, and cargo inspection, to name afew. Some of these applications may operate at energy levels as high as450 keV.

Referring now to FIG. 6, there is shown a multilayer optic 110 includinga plurality of layers 113 a-113 n, one on top of the other, extendingbetween an input face 112 and an output face 114 having a polygonalprofile. As illustrated, the middle layer of the multilayer optic 110 islayer 113mid. Except for layer 113mid, all of the layers include aphoton redirection region positioned between the input face 112 and theoutput face 114. It should be appreciated, however, that layer 113midmay include a photon redirection region, or that other layers inaddition to 113mid may lack a photon redirection region. The designshown allows diverging electromagnetic radiation to be input into theinput face 112, redirected by the optic multilayers, and output from theoutput face 114 into a parallel fan beam. Depending upon where theoutput face 114 is located relative to the photon redirection regions,the fan beams may be parallel or near parallel or may be somewhatdivergent but still focused relative to the input of electromagneticradiation. Additionally, the conformal nature of the individual layersallows for the multilayer optic 110 to be utilized in a vacuumenvironment.

Referring to FIG. 7, there is shown a multilayer optic 210 that includesan input face 212 and an output face 214. As with the embodiment shownin FIG. 6, the multilayer optic 210 includes individual layerssandwiching a mid-layer. The design shown allows for a focused parallelfan beam output. As with the previously described embodiments, theconformal nature of the individual layers allows the multilayer optic210 to be used in a vacuum environment.

FIG. 8 illustrates a multilayer optic 310 having an input face 312 andan output face 314. The layers have been positioned over a cone 150,which serves as a blank or mold for the individual layers. Through thisdesign, the output beam exiting the output face 314 is shaped into acurved output, which can be coupled to a singly curved diffractingcrystal (not shown) to enable the creation of a fan beam of highlymonochromatic radiation. Monochromatic radiation is used in severaldifferent applications, including, for example, X-ray diffraction.Highly monochromatic radiation is radiation within a very narrow energyrange approximately equal to that produced by diffracting from a singlecrystal. The singly curved diffracting crystal can be formed of anysuitable material, such as, for example, mica, silicon, germanium, orplatinum and curved so that the crystal conforms to the surface of, forexample, a cone or cylinder. The suitability of any material for use asthe diffracting crystal is dependent upon the diffraction intensity andthe lattice spacing of the material. It should be appreciated that themultilayer optic 310 should be positioned between the source of theelectromagnetic radiation and the diffracting crystal.

Placing a filter at the input or the output faces of the optics in FIGS.5-7 will make the output radiation from these opticsquasi-monochromatic. Quasi-monochromatic radiation is radiation within alimited wavelength range that is greater than the highly monochromaticrange but less than the full Bremsstrahlung spectrum from an X-raysource.

FIGS. 9-12 illustrate various other potential embodiments of multilayeroptics. FIGS. 9 and 10 illustrate multilayer optics that have outputfaces in a photon redirection region, thereby allowing such optics toemit highly diverging beams. FIGS. 11 and 12 illustrate multilayeroptics whose output faces are dimensionally smaller than theirrespective input faces, allowing such optics to emit highly focusedbeams.

Referring now to FIG. 13, next will be described an apparatus for use informing a multilayer optic. Specifically, a multilayer optic depositionassembly 400 is shown including a deposition chamber 402 and a movableshutter apparatus 410. The deposition chamber 402 may be utilized insuitable deposition techniques, including, for example, vapordeposition, or thermal spray deposition. Suitable vapor depositiontechniques include sputtering, ion implantation, ion plating, laserdeposition, evaporation, and jet vapor deposition. Evaporationtechniques may include thermal, electron-beam, or any other suitabletechnique resulting in appreciable deposition of material. Suitablethermal spray deposition includes combustion, electric arc, and plasmaspray. The deposition chamber 402 includes an inputting apparatus 404for allowing ingress of deposition materials into the deposition chamber402. It should be appreciated that the inputting apparatus 404 mayinclude numerous inlet nozzles, each being associated with a specificdeposition material. A blank 420 is positioned within the depositionchamber 402. The blank 420 may be a core 50 or a cone 150, describedpreviously with regard to the embodiments illustrated in FIGS. 4 and 8,or it may be a substrate serving as a support mechanism for depositedlayers. It should be appreciated that the blank 420 can assume virtuallyany suitable geometric configuration consistent with the desired beamprofile. Examples of the almost infinite number of suitable geometricconfigurations include a circular wafer, a rectangular prism, a cone, acylinder, and an egg-shape, to name a few.

The shutter apparatus 410 enables the formation of a multilayer opticwherein the individual layers have a photon redirection region.Specifically, as a deposition material is input into the depositionchamber 402 through the inputting apparatus 404, the shutter apparatus410 moves in a direction A relative to the blank 420. If the speed ofthe shutter apparatus 410 decreases as it moves in the direction A, anincreasing amount of deposition material will contact the blank 420 inthe direction A, thereby enabling the formation of a multilayer opticwith individual layers having different thicknesses and having photonredirection regions. Control of the movement and velocity of the shutterapparatus 410 may be accomplished electronically with a digitalcontrolling mechanism, such as a microcontroller, microprocessor, orcomputer. Alternatively, control of the movement may be accomplishedmanually, or mechanically, such as, pneumatically, hydraulically, orotherwise.

By moving the shutter apparatus 410 along direction A as each depositionmaterial is input through the inputting apparatus 404 into thedeposition chamber 402, the individual layers can be deposited upon theblank 402, and a multilayer optic having conformal individual layers,like the multilayer optic 110, can be formed. In forming a multilayeroptic like the multilayer optic 110, the first layer to be laid down maybe the mid-layer 113mid. Then, the subsequent layers leading to andincluding layer 113 a can be deposited. Then, the partially formedmultilayer optic can be turned over and the layers leading to andincluding layer 113 n can be deposited. Further, assuming a constantrate of deposition material being injected into the deposition chamber402, if the shutter apparatus 410 is programmed to begin with a firstvelocity, transition into a second different velocity, and thentransition back to the first velocity, a multilayer optic like themultilayer optic 210 can be formed. It should be appreciated that thedeposition rate of the deposition material in the deposition chamber 402may be altered as well.

Instead of utilizing a shuttle apparatus 410, it is possible to move atvarying speeds the inputting apparatus 404 relative to the blank 420.Further, it is possible to move at varying speeds the blank 420 withinthe deposition chamber 402 relative to the inputting apparatus 404.

Referring to FIG. 14, there is shown a multilayer optic depositionassembly 500 that includes a deposition chamber 502 and the movableshutter 410. The deposition chamber 502 includes the apparatus 404 thatis the source of a vapor stream and a pair of rotatable spindles 505.The spindles 505 are capable of rotating in a direction B. Further, thespindles 505 each include a pointed end that comes into contact with andholds the blank 420. By rotating the spindles 505 in the same directionB the blank 420 can be rotated while deposition material is introducedinto the deposition chamber 502 through the inputting apparatus 404.Movement of the shutter apparatus 410 in the direction A and rotation ofthe blank 420 in the direction B will enable the formation of amultilayer optic such as the multilayer optic 10. Alternatively, thespindles 505 can remain in a non-rotating state during a first set ofdeposition steps to form the layers 113mid to 113 a. Then, the spindles505 can be rotated to turn the partially formed multilayer optic onehundred and eighty degrees around to allow for a second set ofdeposition steps to form the layers leading to and including 113 n toform the multilayer optic 110.

Instead of utilizing a shutter apparatus 410, it is possible to move atvarying speeds the inputting apparatus 404 relative to the blank 420while the blank 420 is being rotated by the spindles 505. Further, it ispossible to move at varying speeds the spindles 505 and the blank 420within the deposition chamber 402 relative to the inputting apparatus404.

FIG. 15 illustrates process steps for forming a multilayer optic inaccordance with an embodiment of the invention. At Step 600, a firstmaterial having a pre-determined index of refraction with apre-determined photon transmission coefficient is laid down. The firstmaterial is laid down on a blank or substrate, which may be a core, acone, or a polygonal support mechanism. It should be appreciated thatthe blank or substrate may be incorporated within the multilayer optic,such as the core 50, or may serve merely as a mold, like cone 150. Then,at Step 605, a second material having a second index of refraction witha second photon transmission coefficient is deposited on the firstmaterial in such a way as to be conformal and have minimal void spaces.It should be appreciated that each individual layer may be formed atthicknesses in the range of one nanometer to thousands of nanometers.After Step 605, the Steps 600 and 605 can be sequentially repeated toprepare multiple pairs of layers, with each pair having one layer havinga first index of refraction with a first photon transmission coefficientand a second layer having a second index of refraction with a secondphoton transmission coefficient. The deposition of the first and secondmaterials may be accomplished by any number of suitable processes, suchas, for example, vapor deposition, thermal spray deposition, orelectroplating. Examples of suitable vapor deposition techniques includesputtering, ion implantation, ion plating, laser deposition (using alaser beam to vaporize a material or materials to be deposited),evaporation, or jet vapor deposition (using sound waves to vaporize amaterial or materials to be deposited). Evaporation techniques may bethermal, electron-beam or any other suitable technique that will resultin appreciable deposition of material. Examples of suitable thermalspray deposition techniques include combustion, electric arc, and plasmaspray.

It should be appreciated that during the deposition process, thepartially formed multilayer optic may be rotated, oscillated, or moved,it may be turned, and it may be subjected to a deposition processwhereby the deposition material is deposited at different rates alongthe axis of the multilayer optic. In this way, multilayer optics can beformed with various configurations and profiles that will allow for agreater amount of electromagnetic radiation to be collected from asource at the input of the optic, parallel or near parallel beams ofelectromagnetic radiation to be output from the multilayer optic, or thebeams of electromagnetic radiation output from the multilayer optic maybe shaped into pencil beams, fan beams, or curved in an arc, as anexample.

Multilayer optics in accordance with embodiments of the invention may beused in various industrial applications. For example, a multilayer opticformed to emit a quasi-parallel beam having a circular cross-section mayfind utility in X-ray diffraction and backscatter, such asnon-destructive examination, applications. A multilayer optic formed toemit a slightly focused beam with a circular cross-section may findutility in X-ray diffraction, X-ray fluorescence, and non-destructiveexamination applications. Multilayer optics formed to emit a highlyfocused beam having a circular cross-section may find utility in X-rayfluorescence and non-destructive examination applications. Multilayeroptics formed to emit a slightly diverging beam having a circularcross-section may find utility in computed tomography and X-raydiagnostic system applications. Multilayer optics formed to emit ahighly diverging beam having a circular cross-section may find utilityin non-destructive examination applications requiring an increasedfield-of-view, and in medical interventional imaging and treatmentsrequiring an increased field-of-view, such as the imaging and treatmentof large tumors.

Alternatively, multilayer optics formed to emit a quasi-parallel fanbeam in one plane that is quasi-parallel, slightly focused, highlyfocused, slightly diverging, or highly diverging in a direction parallelto the fan would produce a beam having a rectangular cross-section thatmay find utility in non-destructive examination applications.

Multilayer optics formed to emit a fan beam in one plane that isquasi-parallel, slightly focusing, highly focusing, slightly diverging,or highly diverging in a direction transverse to the plane may findutility in computed tomography, X-ray diagnostic system, andnon-destructive examination applications. The fan beam may have adivergence the same as or greater than that of the source.

Multilayer optics formed to emit a fan beam in one plane that isslightly or highly diverging in the direction transverse to the fan beamplane may find utility in medical interventional applications, such asclose-up imaging to increase field-of-view. The divergence in thedirection transverse to the fan beam plane is equal to or greater thanthe source divergence.

A multilayer optic coupled to a diffracting crystal may produce aquasi-parallel monochromatic fan beam that may find utility, providedthe intensity is great enough, in medical imaging and interventionaltreatments. Such monochromatic imaging would reduce a patient's dose ofX-rays while increasing the resolution.

While the invention has been described in detail in connection with onlya limited number of embodiments, it should be readily understood thatthe invention is not limited to such disclosed embodiments. Rather, theinvention can be modified to incorporate any number of variations,alterations, substitutions or equivalent arrangements not heretoforedescribed, but which are commensurate with the spirit and scope of theinvention. Additionally, while various embodiments of the invention havebeen described, it is to be understood that aspects of the invention mayinclude only some of the described embodiments. Accordingly, theinvention is not to be seen as limited by the foregoing description, butis only limited by the scope of the appended claims.

1-34. (canceled)
 35. A method for forming an optic, comprising: forminga first solid phase layer, characterized by a first index of refraction,onto a blank; and forming on the first solid phase layer a second solidphase layer, characterized by a second index of refraction; whereinbetween said first solid phase layer, said blank, and said second solidphase layer are at least two photon redirection regions.
 36. The methodof claim 35, wherein said forming comprises vapor depositing, thermalspray depositing, or electroplating.
 37. The method of claim 36, whereinsaid vapor depositing comprises sputtering, ion implantation, ionplating, laser deposition, evaporation, or jet vapor deposition.
 38. Themethod of claim 36, wherein said thermal spray depositing comprisescombustion, electric arc, or plasma spray.
 39. The method of claim 35,further comprising altering a forming rate of said forming.
 40. Themethod of claim 39, wherein said forming comprises depositing, andwherein said depositing comprises altering a rate of deposition.
 41. Themethod of claim 40, wherein said altering comprises moving a source ofdeposition material or the blank relative to each other.
 42. The methodof claim 40, wherein said altering comprises moving the blank relativeto a source of deposition material.
 43. The method of claim 40, whereinsaid altering comprises: providing a shutter; and moving the shutteralong an axis of the blank at a changing velocity.
 44. The method ofclaim 43, comprising rotating or oscillating the blank during saidforming steps.
 45. The method of claim 43, comprising controlling theshutter electronically, mechanically, or manually.
 46. The method ofclaim 44, wherein said electronically controlling is performed throughthe use of a computer, microcontroller, or microprocessor.
 47. Themethod of claim 35, wherein said forming a first solid phase layercomprises forming the first solid phase layer on a substrate.
 48. Themethod of claim 47, wherein said substrate serves as a mold and isremovable from a formed optic.
 49. The method of claim 48, wherein themold comprises a cone-shaped core and wherein said forming stepscomprise forming said first and second solid phase layers partiallyaround the core.
 50. The method of claim 49, comprising abutting adiffracting crystal against either an input face or an output face of aformed optic.